SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f8fa2331623e02fc032ac80a048555916e9e0d3df4e5420dbbaa3f4d001ce7b' 
  AND token = '1BT3DMK8BrLkAVgVWKbYZY9fFAJf9GJDz7IjMN+zgJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}